Improvement in forms for forming watch-case backs



F. H. wlL'BY. Formsfr Forming Watch-Case Backs.

No. 159,993 f. Patented Feb. 16,1875. l

@mw Y TH-E GRAPHIC CO.PHOTOLIT`H.39 8:41 PARK PLAGE,N.Y.

NTTED STATES PATENT OFFICE.

FRITZ H. WILBY, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN FORMS FOR FORMING WATCH-CASE BACKS.

Specification forming part of Letfe s Patent No. 159,993, dated February 16, 1875; application tiled January 9, 1875.

CAsE B.

To all whom it may concern:

Be it known that I, FRITZ H. VILBY, of the city and county of Philadelphia, in the State of Pennsylvania, have invented an Improvement in Watch Gase Combination- Chucks, of which the following is aspecication:

My invention consists of a chuck for makin g watchcases, the chuckv having the shape of a finished back, in combination with a clamping-ring for confining a back thereon,`

A is the chuck upon which the back C is placed, and held down by means of the clamping-ring B, connected therewith by means of the screw`threads a b. The chuck outside of the Screw-thread a, except the narrow surface' c, against which the lip d of the ring rests, is of the shape and dimensions assumed by the iinished back. The clamping-ring B is screwed down to its place, as shown in Fig. 2. Then a burnisher is used for pressing down the back C until it fits the chuck, as shown in Fig. 3, to form the flat back D. For making swelled instead of flat backs, the chuck is made of the corresponding form the finished back has to. assume.

I claim as my invention- The chuck A, in combination with the clamping-rin g B, for making the nished back, substantially as described.

FRITZ H. VVILBY. Witnesses:

THOMAS J. BEWLEY, STEPHEN UsTIoK. 

